Calibration of a push-pull driver is conventionally performed relative to an external or off-die resistor. Process, voltage and temperature (PVT) variation differences between the push-pull driver die and the off-die resistor may, however, lead to errors.
Calibration of a push-pull driver is conventionally performed at voltages that differ from normal operating voltages, which may also lead to errors.
Driver circuits are conventionally calibrated individually and single-ended. Individual and singled-ended calibration of the driver currents may, however, lead to errors when the driver circuits are used differentially during operation.
Driver currents are conventionally calibrated first and the calibrated driver currents are used to calibrate transmit terminations. Errors in calibration of the driver currents may lead to errors in calibration of the termination circuits.
Errors may be exacerbated at smaller scale integrated circuit fabrication technologies.
Errors may be overcome with additional design features, but at a cost of added area and power consumption.
In the drawings, the leftmost digit(s) of a reference number identifies the drawing in which the reference number first appears.